I'm confused,how can I change the sound output in LXDE? There's not even a single option anywhere unlike other environments.

I've tried doing anything with alsamixerbut still nothing, the output device is the HDMI audio of a Radeon HD card.

Edit: As it Turns out i was able to change the ouput device, but i had to use Gnome for that and its Gnome Sound applet, that is log out and log in once in Gnome change the device, log out and log back in LXDE.

First of all, try lspci and lsusb to check if the device you need is seen by the system.

Secondly in alsamixer try pressing F6, which will let you choose the sound card (I really don't know if this is needed tbh).

And another tip for alsamixer: it doesn't show all parameters when u start it, some are hidden on the right so you just have to go to the right to see them all, I believe there is an output chooser. And also in alsa see if you are viewing the needed items (F5 will show all parameters available).

I am using Ubuntu 12.04 64bits and I recently installed XFCE-4 Desktop.
When I first logged in xfce-4 I noticed there was no sound at all (Rythmbox, games, etc).
And I found no icon anywhere to adjust the sound.